The invention relates to tanks for cryogenic liquids, said tanks being intended for installation in motor vehicles and which consists of an outer container and of an inner container suspended in the latter, the suspension being formed by spatially arranged tension or compression struts of low thermal conductivity which compensate for displacements of the inner container due to thermal expansion differences.
A cryotank for rockets is known from U.S. Pat. No. 4,481,778. The bands serving for suspension surround short struts which are articulated on connectors with play on both sides. In the event of the high acceleration occurring in the longitudinal direction during starting, the struts are laid against the connectors. Owing to its application in rocket technology, however, this design does not afford either sufficient cold insulation (the struts are highly effective heat bridges) or sufficient freedom of movement for the inner container.
DE-A-101 28 516 discloses a generic tank for cryogenic liquids, which is intended for use in motor vehicles, with spatially arranged tension or compression struts which engage on a tube mounted centrally in the inner container. These struts are again very strong and thermally conductive components, but cannot withstand more pronounced shocks, let alone collisions.
Further, GB 2 025 029 discloses a storage container for liquid gases, the inner container of which is centered in the outer container by means of the repulsion of permanent magnets.
None of these designs can satisfy the special requirements arising in the event of use in motor vehicles. These are, on the one hand, that the heat insulation is to be particularly good, in order to minimize evaporation (the vehicle must be ready to drive even after being at a standstill for a week and it must be possible to walk around in the garage with a cigarette); and, on the other hand, the support of the inner container must withstand movements and accelerations in all directions, not only those in the event of a collision, but also those constantly occurring due to unevennesses of the road. The object of the invention is to take into account these contrasting requirements in an optimum way.